Tag: inborn errors of metabolism

Quizzes (1) Questions (15)

Questions Related to inborn errors of metabolism

Multiple choice bio-chemistry inborn errors of metabolism haemophilia and colour blindness non infectious diseases keeping diseases away

A daughter will not normally be colourblind, unless her mother is ...... and her father is ....

  1. Carrier, colour blind

  2. Colour blind, normal

  3. Colour blind, carrier

  4. Carrier, carrier
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Daughters inherit x chromosomes of father & mother respectively since one x chromosome masks the effect of another x chromosome, a daughter will only be colourblind if her mother is a carrier & father is colorblind.

So, the correct option is 'Carrier, colour blind'.

Multiple choice bio-chemistry inborn errors of metabolism haemophilia and colour blindness non infectious diseases keeping diseases away

Select the incorrect statement from the following :

  1. Baldness is a sex limited trait

  2. Linkage is an exception to the principle of independent assortment in heredity.

  3. Galactosemia is an inborn error of metabolism

  4. Small population size results in random genetic drift in a population
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Baldness is a sex-influenced trait, not a sex-limited trait. Sex-influenced traits are expressed in both sexes but are more common in one (like male pattern baldness).

Multiple choice bio-chemistry inborn errors of metabolism haemophilia and colour blindness non infectious diseases keeping diseases away

If both parents are bald and their first female child is normal, then the chances of baldness in their second male child is?

  1. $50$%
  2. $100$%
  3. $25$%
  4. $0$%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Male pattern baldness is a sex-influenced trait. In males, it acts as a dominant trait, while in females, it acts as a recessive trait. If both parents are bald, the male child has a 100% chance of inheriting the allele and expressing the phenotype.

Multiple choice bio-chemistry inborn errors of metabolism haemophilia and colour blindness non infectious diseases keeping diseases away

The possibility of a female becoming haemophilic is extremely rare because the mother of such a female has to be at least (i) and father should be (ii). 

  1. (i) Haemophilic, (ii) Carrier

  2. (i) Carrier, (ii) Haemophilic

  3. (i) Haemophilic, (ii) Normal

  4. (i) Haemophilic, (ii) Haemophilic
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

  • Haemophilia is genetically due to the presence of a $recessive$ sex-linked gene h, carried by the X chromosome. 
  • A female becomes haemophilic only when both Its X chromosomes carry the gene $(XhXh)$. However, such females (mothers) generally die before birth because the combination of these two recessive alleles is lethal. A female having only one allele for haemophilia $(XX^h)$ appears normal because of the allele for normal blood clotting present on the other X-chromosome is dominant. Such females are known as carriers. 
  • In the case of males, a single gene for the defect is able to express itself as the Y-chromosome is devoid of any corresponding allele $(Xh^Y)$.
  • Thus, the possibility of a human female becoming haemophilic is extremely rare because she has to be homozygous recessive for the trait, i.e., her father must be a haemophilic and mother must be at least a carrier.

Multiple choice bio-chemistry inborn errors of metabolism haemophilia and colour blindness non infectious diseases keeping diseases away

Correct pathway for synthesis of skin pigment is?

  1. Tyrosine - dopa - melanin - dopaquinone

  2. Tyrosine - dopaquinone - dopa - melanin

  3. Dopa - tyrosine - dopaquinone - melanin

  4. Tyrosine - dopa - dopaquinone - melanin

  5. Tyrosine - melanin - dopaquinone - dopa.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The biochemical pathway for melanin synthesis involves the conversion of the amino acid tyrosine into dopa, then into dopaquinone, and finally into melanin.